Brain Health 1 Flashcards
drugs v neurotransmitters
Neurotransmitters = chemicals that direct neuronal activity and behavior Drugs = chemicals that mimic, enhance, or block the action of neurotransmitters
classification of psychoactive drugs
Sedative Hypnotics and Anxiolytics Antipsychotics Antidepressants Psychomotor Stimulants Narcotic Analgesics Psychedelics and Hallucinogens
sedative hypnotics and anxiolytics
Examples: Alcohol, Barbiturates (anesthesia), Benzodiazepines (valium, xanax, etc), Ketamine
Effects: range from reduced anxiety to sleep to coma/death
NTs affected: GABA agonists
tolerance
the diminished response to a drug over time, must take more and more to get the same initial effect.
cross tolerance
someone who is tolerant to the effects of a certain drug also develops a tolerance to another drug.
Alcohol, Barbiturates, and Benzodiazepine show cross-tolerance because affect the same GABA receptor.
fetal alcohol syndrome
Alcohol passes through the placenta and prevents enough nutrition and oxygen from getting to the fetus leading to:
(FAS is incurable)
Small brains and head, underdeveloped gyri and sulci, abnormal clusters of cells and misaligned cells in cortex, learning disabilities to mental retardation (poor language and math skills), hyperactivity, lack of focus, mood swings, abnormal facial features (smooth ridge between the upper lip and nose, small and wide-set eyes, very thin upper lip), below average height and weight, poor coordination, problems with vision and hearing, heart problems, kidney defects.
psychosis
inability to discern between reality and delusions/hallucinations (can develop in people without schizophrenia)
psychosis extras
Examples Neuroleptics: (older) Chlorpromazine, Haloperidol (Haldol), (newer) Clozapine, Zyprexa, Risperdal
Effects: reduce motor activity, reduce hallucinations and delusions, can cause Parkinsonian symptoms or tics (Older meds: dyskinesia -chewing movement, darting tongue, drooling, sedated, difficulty thinking)
NTs affected: Dopamine antagonists
how do antipsychotics work
Antipsychotics work by binding to D2 receptors and blocking dopamine from binding so that the channel does not open.
antidepressants
Examples: MAO inhibitors, Tricyclics, SSRI’s
Effects: reduction of anxiety/depression, possible sexual dysfunction, sedation, dry mouth, blurred vision, memory impairment
NTs affected: serotonin, norepinephrine, histamine, acetylcholine, dopamine agonists; mostly block destruction and reuptake of serotonin and norepinephrine
psychomotor stimulants
All stimulants increase the activity of neurons in both the CNS and PNS. Also called “Uppers”.
Effects:
Enhances alertness, awareness, wakefulness, endurance, productivity and motivation, increases arousal, perception, locomotion, heart rate and blood pressure, diminishes requirement for food and sleep, improves mood, relieves anxiety, causes euphoria, racing speech and thoughts, paranoia
three groups of psychomotor stimulants
General Stimulants
Behavioral Stimulants
Psychedelics
general stimulants
Examples: Caffeine, Nicotine
Effects: enhances the activity of the nervous system, Caffeine – reduces drowsiness, increases alertness, enhances mood, improves energy output, increases relaxation and relieves depression but side effects are dizziness, irritability, nausea, and nervousness, headache with withdrawal Nicotine – euphoria and relaxation, alertness and arousal also causes lung cancer, seizures, chest pain, irregular heartbeat
NTs affected: Caffeine - adenosine antagonist but glutamate, dopamine, acetylcholine, and serotonin agonist Nicotine - acetylcholine agonist
caffeine mechanism of action
Normally, Adenosine is a neuromodulator and when it binds to receptors, neural activity slows down facilitating sleep and dilating blood vessels for adequate oxygenation during sleep.
Caffeine blocks A2 adenosine G-protein coupled receptors which inhibit an enzyme that normally breaks down a second messenger, cAMP (cyclic adenosine monophosphate). As cAMP increases, more glucose is produced in the cell, which increases cell activity.
Caffeine activates the HPA axis - neural circuits signal the Pituitary gland to release ACTH which targets the Adrenal Glands to secrete adrenaline for burst of energy.
caffeine tolerance
Regular caffeine intake leads to slight tolerance, withdrawal, and therefore dependency. First, the body will produce more adenosine receptors in response to too much caffeine, causing tolerance.